There are conventionally known semiconductor packages (semiconductor devices) in which a semiconductor chip is bonded by flip chip bonding. A semiconductor chip to be mounted in such a semiconductor package has solder bumps (bump electrodes) formed on it to allow flip chip bonding (for example, see Patent Document 1 listed below).
FIGS. 29 to 31 are schematic sectional views showing the structure of a conventional semiconductor device disclosed in Patent Document 1. In the conventional semiconductor device, as shown in FIG. 29, an electrode pad portion 1002 is formed on the top face of a semiconductor substrate 1001. It should be understood that on the top face of the semiconductor substrate 1001, a circuit (unillustrated) such as an IC or LSI has been fabricated. Moreover, on the top face of the semiconductor substrate, a protection layer 1003 for protecting the top face of the semiconductor substrate 1001 is formed. The protection layer 1003 has an opening 1003a through which a predetermined region on the electrode pad portion 1002 is exposed. Moreover, the protection layer 1003 is so formed as to overlap a peripheral part of the electrode pad portion 1002, with the result that the protection layer 1003 has a step part 1003b formed in it.
Moreover on the electrode pad portion 1002, via a barrier metal layer 1004, a bump electrode 1005 is formed. The barrier metal layer 1004 is formed on the electrode pad portion 1002 such that a peripheral part 1004a of the barrier metal layer 1004 rests on a region of the protection layer 1003 overlapping the electrode pad portion 1002. That is, a circumferential end part 1004b of the barrier metal layer 1004 is formed on the region of the protection layer 1003 overlapping the electrode pad portion 1002.
Moreover, as shown in FIG. 30, the semiconductor substrate 1001 having the bump electrode 1005 formed on it is arranged face down above a printed circuit board 1006—in such a way that the top face (circuit face) of the semiconductor substrate 1001 faces the printed circuit board 1006 —, and is connected by the bump electrode 1005 to an electrode 1007 on the printed circuit board 1006 on a flip chip basis.
Patent Document 1: JP-A-2007-13063